In a recent U.S. Supreme Court’s decision Gross v. FBL Financial Services, Inc.,decided June 18, 2009, the U.S. Supreme Court held that an employee who sues his or her employer for age discrimination must prove that his or her age was the “but for” cause of an adverse employment decision, even if the employee has some evidence that age was a factor in the decision. This decision draws a bright line between the claims of age discrimination and claims of all other forms of discrimination.

In the Gross case, the plaintiff sued his employer alleging that he was demoted in violation of the Age Discrimination in Employment Act (the “ADEA”). At trail, the district court employed the burden-shifting analysis prevalent in discrimination cases by instructing the jury to return a verdict for plaintiff if he proved that he was demoted and his age was a “motivating factor” in the decision to demote. The trial court told the jury that age was a motivating factor if it played a part in plaintiff’s demotion.

After appeal, the U.S. Supreme Court held that the familiar burden-shifting framework of all other discrimination cases does not apply to cases arising under the ADEA. Rather, an employee who files an ADEA disparate treatment claim must prove, by a preponderance of the evidence, that age was the “but for” cause of an adverse employment action. While the Court did not answer the precise question that was certified – whether direct evidence of discrimination was necessary in a mixed motive case not arising under Title VII – the decision was more prohibitive to age discrimination claimants. By implication, claims under ADEA would require direct evidence, eliminating any burden shifting substitute for direct evidence.

Based on the new standard, age discrimination claimants with indirect evidence of age discrimination should be prevented from even reaching a jury unless there is direct evidence that age was the “but for” cause of the adverse employment action. Because the burden-shifting analysis under ADEA is now rejected by the U.S. Supreme Court, it follows that the ability to challenge an employer’s action by claiming that such actions are pre-textual is now changed. While it remains to be seen how lower courts will interpret the new decision, it is nevertheless has created a burden not shared by any other discrimination claimants.